35
ECOM II
The results of the multicollinearity test are presented in a tabbed sheet.
A multiple regression is undertaken for each of the environmental variables in turn
with all the other environmental variables acting as the independent variables. Values
of R squared close to 1 or Variance inflation factors (VIF) well above 1 are indicative
of multicollinearity and you should consider removing one of a group of highly
correlated variables from the analysis. High VIF values are highlighted in red. Use
stepwise regression
 and 
Variable Selection
 to identify which environmental variables
to retain for your analysis
If you should obtain very large values for VIF it is likely that some of your variables
add up to a constant. This often happens if you are using dummy variables see
Linear Combinations of Environmental Variables
.
7.7
Circular environmental variables
Two common examples of circular data are direction (aspect) and day of the year.
Aspect (or compass direction of a slope) can be transformed by trigonometric
functions (Roberts 1986). The simplest way to do this is to create two variables,
Copyright 2004  PISCES Conservation Ltd





Actions web hosting footer




 

 

 

 

Home | About Us | Network | Compare Plans | Support | FAQ | Control Panel | Order Online | Sitemap | Contact

Terms Of Service

servlet web hosting

 

Our web partners: Web Hosting PHP Jsp Web Hosting Java Web Hosting Jsp Web Hosting Cheapest Web Hosting  Java Web Hosting

Cheap Web Hosting Java Hosting Cheapest Hosting Quality Web Templates Best Web Templates Web Design Templates

Java Web Hosting Cheap Hosting Cheap Web Hosting Jsp Web Hosting Tomcat Web Hosting

Quality Web Hosting Best Web Hosting Java Web Hosting

Actionswebhosting.com Business web hosting division of Vision Web Hosting Inc. All rights reserved.